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HARRY POTTER AND THE CHAMBER OF SECRETS
There's a specific part in this book explaining...
Harry hearing the voices but actually was a hissing of a snake.
Harry hearing the words kill and rip.
Harry being filled with panic as he tries to find whether that voice he heard is trying to kill someone or not.
Ron and Hermione explaining that hearing voices in the wizarding world is not a good sign.
A part of the book contains the information of Harry hearing voices. When Harry received a detention after being caught on a night walk, Ron was told by Professor McGonagall to help Filch in polishing and cleaning the trophies in the trophy room.
And one time, a form of wizard duel was held, the coordinators were Lockhart and Snape (assistant). When Draco casted the